[PATCH 3/5] xfs: cross-reference rmap records with free space btrees

Darrick J. Wong
2022-12-30T22:52:42Z

Strengthen the rmap btree record checker a little more by comparing
OWN_AG reverse mappings against the free space btrees, the rmap btree,
and the AGFL.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/scrub/bitmap.c | 33 +++++++++++++++++++++++++
fs/xfs/scrub/bitmap.h | 3 ++
fs/xfs/scrub/rmap.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 102 insertions(+)

diff --git a/fs/xfs/scrub/bitmap.c b/fs/xfs/scrub/bitmap.c
index 14caff0a28ce..72fdb6cd69b4 100644
--- a/fs/xfs/scrub/bitmap.c
+++ b/fs/xfs/scrub/bitmap.c
@@ -6,6 +6,7 @@
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
+#include "xfs_bit.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
@@ -262,6 +263,38 @@ xbitmap_disunion(
* For the 300th record we just exit, with the list being [1, 4, 2, 3].
*/

+/* Mark a btree block to the agblock bitmap. */
+STATIC int
+xagb_bitmap_visit_btblock(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *priv)
+{
+ struct xagb_bitmap *bitmap = priv;
+ struct xfs_buf *bp;
+ xfs_fsblock_t fsbno;
+ xfs_agblock_t agbno;
+
+ xfs_btree_get_block(cur, level, &bp);
+ if (!bp)
+ return 0;
+
+ fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
+ agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+
+ return xagb_bitmap_set(bitmap, agbno, 1);
+}
+
+/* Mark all (per-AG) btree blocks in the agblock bitmap. */
+int
+xagb_bitmap_set_btblocks(
+ struct xagb_bitmap *bitmap,
+ struct xfs_btree_cur *cur)
+{
+ return xfs_btree_visit_blocks(cur, xagb_bitmap_visit_btblock,
+ XFS_BTREE_VISIT_ALL, bitmap);
+}
+
/*
* Record all the buffers pointed to by the btree cursor. Callers already
* engaged in a btree walk should call this function to capture the list of
diff --git a/fs/xfs/scrub/bitmap.h b/fs/xfs/scrub/bitmap.h
index 65a6c5a92c7a..ab67073f4f01 100644
--- a/fs/xfs/scrub/bitmap.h
+++ b/fs/xfs/scrub/bitmap.h
@@ -106,4 +106,7 @@ static inline int xagb_bitmap_walk(struct xagb_bitmap *bitmap,
return xbitmap_walk(&bitmap->agbitmap, fn, priv);
}

+int xagb_bitmap_set_btblocks(struct xagb_bitmap *bitmap,
+ struct xfs_btree_cur *cur);
+
#endif /* __XFS_SCRUB_BITMAP_H__ */
diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
index 415d8e9918da..b8e82f5b84f4 100644
--- a/fs/xfs/scrub/rmap.c
+++ b/fs/xfs/scrub/rmap.c
@@ -7,13 +7,17 @@
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
+#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
+#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_rmap.h"
#include "xfs_refcount.h"
#include "xfs_ag.h"
#include "xfs_bit.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
@@ -51,6 +55,7 @@ struct xchk_rmap {
/* Bitmaps containing all blocks for each type of AG metadata. */
struct xagb_bitmap fs_owned;
struct xagb_bitmap log_owned;
+ struct xagb_bitmap ag_owned;

/* Did we complete the AG space metadata bitmaps? */
bool bitmaps_complete;
@@ -291,6 +296,9 @@ xchk_rmapbt_mark_bitmap(
case XFS_RMAP_OWN_LOG:
bmp = &cr->log_owned;
break;
+ case XFS_RMAP_OWN_AG:
+ bmp = &cr->ag_owned;
+ break;
}

if (!bmp)
@@ -343,9 +351,26 @@ xchk_rmapbt_rec(
return xchk_rmapbt_mark_bitmap(bs, cr, &irec);
}

+/* Add an AGFL block to the rmap list. */
+STATIC int
+xchk_rmapbt_walk_agfl(
+ struct xfs_mount *mp,
+ xfs_agblock_t agbno,
+ void *priv)
+{
+ struct xagb_bitmap *bitmap = priv;
+
+ return xagb_bitmap_set(bitmap, agbno, 1);
+}
+
/*
* Set up bitmaps mapping all the AG metadata to compare with the rmapbt
* records.
+ *
+ * Grab our own btree cursors here if the scrub setup function didn't give us a
+ * btree cursor due to reports of poor health. We need to find out if the
+ * rmapbt disagrees with primary metadata btrees to tag the rmapbt as being
+ * XCORRUPT.
*/
STATIC int
xchk_rmapbt_walk_ag_metadata(
@@ -353,6 +378,9 @@ xchk_rmapbt_walk_ag_metadata(
struct xchk_rmap *cr)
{
struct xfs_mount *mp = sc->mp;
+ struct xfs_buf *agfl_bp;
+ struct xfs_agf *agf = sc->sa.agf_bp->b_addr;
+ struct xfs_btree_cur *cur;
int error;

/* OWN_FS: AG headers */
@@ -370,6 +398,39 @@ xchk_rmapbt_walk_ag_metadata(
goto out;
}

+ /* OWN_AG: bnobt, cntbt, rmapbt, and AGFL */
+ cur = sc->sa.bno_cur;
+ if (!cur)
+ cur = xfs_allocbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
+ sc->sa.pag, XFS_BTNUM_BNO);
+ error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
+ if (cur != sc->sa.bno_cur)
+ xfs_btree_del_cursor(cur, error);
+ if (error)
+ goto out;
+
+ cur = sc->sa.cnt_cur;
+ if (!cur)
+ cur = xfs_allocbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
+ sc->sa.pag, XFS_BTNUM_CNT);
+ error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
+ if (cur != sc->sa.cnt_cur)
+ xfs_btree_del_cursor(cur, error);
+ if (error)
+ goto out;
+
+ error = xagb_bitmap_set_btblocks(&cr->ag_owned, sc->sa.rmap_cur);
+ if (error)
+ goto out;
+
+ error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
+ if (error)
+ goto out;
+
+ error = xfs_agfl_walk(sc->mp, agf, agfl_bp, xchk_rmapbt_walk_agfl,
+ &cr->ag_owned);
+ xfs_trans_brelse(sc->tp, agfl_bp);
+
out:
/*
* If there's an error, set XFAIL and disable the bitmap
@@ -411,6 +472,9 @@ xchk_rmapbt_check_bitmaps(

if (xagb_bitmap_hweight(&cr->log_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
+
+ if (xagb_bitmap_hweight(&cr->ag_owned) != 0)
+ xchk_btree_xref_set_corrupt(sc, cur, level);
}

/* Scrub the rmap btree for some AG. */
@@ -427,6 +491,7 @@ xchk_rmapbt(

xagb_bitmap_init(&cr->fs_owned);
xagb_bitmap_init(&cr->log_owned);
+ xagb_bitmap_init(&cr->ag_owned);

error = xchk_rmapbt_walk_ag_metadata(sc, cr);
if (error)
@@ -440,6 +505,7 @@ xchk_rmapbt(
xchk_rmapbt_check_bitmaps(sc, cr);

out:
+ xagb_bitmap_destroy(&cr->ag_owned);
xagb_bitmap_destroy(&cr->log_owned);
xagb_bitmap_destroy(&cr->fs_owned);
kfree(cr);